Fuller’s teasel, barber’s brush, brushes and combs, card teasel, card-thistle, Venus cup teasel, wild teasel.
Common teasel, Dipsacus fullonum L., is a biennial plant that reproduces from seed and is native to Europe. In its first year (sometimes longer), teasel exists as a basal rosette of wrinkled-looking leaves with rounded or scalloped edges and prickly lower midribs; while a rosette, the plant develops a large taproot that can extend over 2 feet long. Later in its life cycle—usually its second year—teasel bolts, sending up an erect flowering stalk that can reach heights of 6 feet. The stems of teasel are angled and prickly with small, downward-curving spines; the stem leaves are opposite, lance-shaped, and fused at the base. These fused leaf bases around the stem form a cup that can collect rain water; this trait distinguishes common teasel from others in the genus. The flower stalks of common teasel support terminal flower heads that are subtended by stiff, spiny bracts that curve upward around and often extend above the flower head. Individual flowers are small, lavender to purple, and tube-shaped. In early bloom, the first flowers to open form a distinctive spiral pattern around the egg-shaped flower heads. The fruit of common teasel is a 4-angled, ridged achene that contains a single seed; a single plant can produce more than 2,000 seeds that have a high germination rate and can remain viable in the soil for over 2 years. After production of seed has occurred, the teasel plant dies, typically leaving a woody skeleton of stems and flowers that can persist for years (and is often used in dried flower arrangements). Photo by: Barry Rice, sarracenia.com, Bugwood.com
Common teasel is related to cut-leaf teasel (Dipsacus laciniatus), which is distinguishable by its deeply-lobed leaves. Although its flowers may resemble those of some thistles, common teasel has puckered leaves with spineless edges and it grows for at least a year as a basal rosette.
Common teasel had numerous historical uses, among those raising the nap on woolen cloth. Introduced to North America in the 1700s, it has since escaped cultivation and has spread across much of the continental U.S. except the northern Great Plains. It is an aggressive invader that outcompetes and displaces desirable forage and other plants. It is generally avoided by grazing animals because of its bitter taste and prickly nature. Common teasel grows in open, sunny habitats with a range in moisture. The plant favors disturbed sites and is commonly found along roadsides and ditches and in abandoned fields and waste areas.
Eliminating a population of common teasel will require a persistent effort using appropriate control method(s) over the span of several years in order to exhaust the seed bank in the soil. Regular monitoring of the site will be necessary to eliminate regrowth. Common teasel does not survive continual unrest such as occurs with regular cultivation.
Cultural Control: The spread of common teasel is only worsened by bare ground or sparse plant stands, so it is important to maintain healthy plant communities. While vegetative cover helps reduce teasel infestations, it does not prevent them; nevertheless, it is advisable to reseed disturbed areas with perennial grasses or other desirable plants.
Burning an infested site can make basal rosettes more visible. While prescribed burns can be used in conjunction with other control measures, they are ineffective by themselves.
Mechanical Control: Cutting, digging and cultivation are effective if the control efforts are repeated often enough to eliminate seed production. Small populations of rosettes can be dug or pulled when the soil is moist; it is important to remove as much of the root system as possible in order to prevent resprouting. Cutting off the stalk can result in regrowth; however, plants will die if cut just before flower heads develop. If flowers have already opened, the stalks and seed heads of cut plants should be bagged and removed from the site in order to prevent seed spread.
More information can be found in the PNW Weed Management Handbook
- Use pesticides with care.
- Apply them only to plants, animals, or sites listed on the label.
- When mixing and applying pesticides, follow all label precautions to protect yourself and others around you.
- It is a violation of the law to disregard label directions.
- Store pesticides in their original containers and keep them out of the reach of children, pets, and livestock.
No biological agent is available for control of common teasel or expected any time soon.
Questions: contact Steve Van Vleet or phone (509) 397 – 6290